The pupæ in both orders attach themselves by means of the adherent feet; those of the Cirripedes to rocks, shells, turtles, drift-wood, ships, etc.,—those of the Rhizocephala to the abdomen of Crabs, _Porcellanæ,_ and Hermit Crabs. The carapace of the Cirripedes becomes converted, as is well-known, into a peculiar test, on account of which they were formerly placed among the Mollusca, and the natatory feet grow into long cirri, which whirl nourishment towards the mouth, which is now open. The Rhizocephala remain astomatous; they lose all their limbs completely, and appear as sausage-like, sack-shaped or discoidal excrescences of their host, filled with ova (Figs. 59, 60); from the point of attachment closed tubes, ramified like roots, sink into the interior of the host, twisting round its intestine, or becoming diffused among the sac-like tubes of its liver. The only manifestations of life which persist in these _non plus ultras_ in the series of retrogressively metamorphosed Crustacea, are powerful contractions of the roots, and an alternate expansion and contraction of the body, in consequence of which water flows into the brood-cavity and is again expelled, through a wide orifice.[8] Fig. 59. Young of Peltogaster socialis on the abdomen of a small Hermit Crab; in one of them the fasciculately ramified roots in the liver of the Crab are shown. Animal and roots deep yellow. Fig. 60. Young Sacculina purpurea with its roots; the animal purple-red, the roots dark grass-green. Magnified. Figs. 61 to 63. Eggs of Tetraclita porosa in segmentation, magnified. The larger of the two first-formed spheres of segmentation is always turned towards the pointed end of the egg. Fig. 64. Egg of Lernæodiscus Porcellanæ, in segmentation, magnified 90 Fig. 59. Young of _Peltogaster socialis_ on the abdomen of a small Hermit Crab; in one of them the fasciculately ramified roots in the liver of the Crab are shown. Animal and roots deep yellow. Fig. 60. Young _Sacculina purpurea_ with its roots; the animal purple-red, the roots dark grass-green. Magnified. Figs. 61–63. Eggs of _Tetraclita porosa_ in segmentation, magnified. The larger of the two first-formed spheres of segmentation is always turned towards the pointed end of the egg. Fig. 64. Egg of _Lernæodiscus Porcellanæ,_ in segmentation, magnified.